The present invention generally relates to image forming apparatuses and more particularly to a xerographic type image forming apparatus.
Recent xerographic image forming apparatuses used in electrostatic photocopier, laser printer, facsimile apparatus and the like have an improved design for facilitating maintenance. Particularly, the apparatus is improved for easiness in removing jammed papers from the apparatus such that a user can do such removal by himself without difficulty. For example, there is a so-called upper transport path type apparatus in which a paper to be printed with an image is transported along a paper transport path passing at an upper side of a photosensitive drum body wherein a top cover lid is provided for accessing the paper in the paper transport path. By simply opening the top cover lid, the user can expose the paper transport path whenever the paper is jammed in the apparatus. Thus, the xerographic image forming apparatus having such a construction is quite easy for removal of the jammed paper.
However, such a prior art xerographic image forming apparatus has a problem in that replacement or cleaning of the drum body is difficult as the drum body is provided inside a body of the printer and cannot be removed easily. Such a cleaning is needed relatively frequently. Further, such an upper transport path type apparatus generally has an image exposing system for projecting the image on the drum at a lower side of the drum. Further, development and cleaning systems are provided at both sides of the drum. Thus, when carrying out inspection of these systems, it is preferred to remove the drum from the body of the apparatus.
In removing the photosensitive body from the apparatus, there arises another problem in that such a removal requires a movement of the photosensitive drum body across the paper transport path passing above the drum and the removal of the jammed paper becomes difficult as the drum body tears the paper when the drum is removed in a state that there is a paper above the drum body. When the apparatus is designed such that the removal of the drum is made simultaneously with the opening of the top cover lid, such a tear of the paper as well as possible damaging of various parts of the system is inevitable. Thus, the conventional upper transport path type apparatus, though providing an easy access to the jammed paper has a problem in the removal or replacement of the drum body. Further, in association therewith, there is a difficulty in the maintenance and inspection of the apparatus